Liability for alleged loss

[gerrysia]

I sent an item to Spain by Royal Mail International Tracked and Signed For. Spanish Post and Royal Mail both state on their websites that the item was delivered to the stated address and was signed for. The buyer claims that he did not receive it and did not sign for anything. The buyer has thus raised a case with Ebay and PayPal has placed his payment to me on hold. I am not bothered about the money.But in principle should I be held liable for the alleged loss ??